Study of the effect of solvents on the influence of electron-donating and electron-withdrawing groups on norbornene-benzamides: an approach using density functional theory

The influence of the medium on the effects of electron-donating ( OCH₃, CH₃, C₂H₅) and electron-withdrawing ( F, Cl, Br, CF₃, NO₂, CN) substituents in norbornene-benzamide derivatives was evaluated using Density Functional Theory (B3LYP/6-311++G(d,p)) calculations, considering chloroform, DMSO, and aqueous medium as implicit solvents. Thus, global (HOMO-LUMO gap, electronegativity, chemical hardness, electrophilicity, and nucleophilicity), local (Fukui functions, dual and multiphilic descriptors), and topological (MEP, ELF, LOL) descriptors were analyzed. Donating groups promoted higher HOMO energies and reduced torsion in the benzamide moiety. Electron-withdrawing groups, in turn, decreased the energy gap and increased the electrophilic character. The electronic properties of the derivatives were similar between the media, indicating electronic stability of the compounds in relation to the media. These results provide information on the structure-reactivity relationships of norbornene-based systems and may guide the development of functional analogs of benzamide for medicinal and materials applications. • Substituent effects dominate electronic properties over solvent influence. • Activating groups raise HOMO and nucleophilicity; deactivating increase electrophilicity. • BHMZ-CH₂CH₃ shows highest energy gap in all solvents studied. • Electronic trends consistent in water and DMSO; slight stabilization in chloroform. • MEP, Fukui and ELF/LOL consistently identify main reactive regions.